From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E4FBC31E5E for ; Wed, 19 Jun 2019 12:18:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 421D921530 for ; Wed, 19 Jun 2019 12:18:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731723AbfFSMSw (ORCPT ); Wed, 19 Jun 2019 08:18:52 -0400 Received: from foss.arm.com ([217.140.110.172]:36714 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726246AbfFSMSw (ORCPT ); Wed, 19 Jun 2019 08:18:52 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EC31EC0A; Wed, 19 Jun 2019 05:18:51 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B1AF53F738; Wed, 19 Jun 2019 05:18:50 -0700 (PDT) Date: Wed, 19 Jun 2019 13:18:48 +0100 From: Will Deacon To: jinho lim Cc: mark.rutland@arm.com, ebiederm@xmission.com, marc.zyngier@arm.com, anshuman.khandual@arm.com, andreyknvl@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, seroto7@gmail.com Subject: Re: [PATCH] arm64: remove useless condition Message-ID: <20190619121848.GE7767@fuggles.cambridge.arm.com> References: <20190619113857.5053-1-jordan.lim@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190619113857.5053-1-jordan.lim@samsung.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 19, 2019 at 08:38:57PM +0900, jinho lim wrote: > dump_instr function checks user_mode internally. > > Signed-off-by: jinho lim > --- > arch/arm64/kernel/traps.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index ccc13b45d9b1..694e78b950ca 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -182,8 +182,7 @@ static int __die(const char *str, int err, struct pt_regs *regs) > print_modules(); > show_regs(regs); > > - if (!user_mode(regs)) > - dump_instr(KERN_EMERG, regs); > + dump_instr(KERN_EMERG, regs); I don't think this is right, because it means we'll now dump the current user instruction on the die() path. Instead, we should probably rename dump_instr to dump_kernel_instr(), and have it return immediately if user_mode(regs). We can also kill __dump_instr completely. Will